UK researchers derive 'na´ve' pluripotent stem cells for the first time

In the first instance of its kind, researchers in the UK have derived very early stage stem cell lines – called 'naive' pluripotent stem cells – from human embryos for the very first time.

The achievement, which was something researchers had been working towards for decades, could lead to a better understanding of how genetic conditions such as Down syndrome developed at the cell level, and create new kinds of treatments to promote healthy cell lines.

"Until now it hasn't been possible to isolate these naive stem cells, even though we've had the technology to do it in mice for 30 years – leading some people to doubt it would be possible," said researcher Ge Guo from the Stem Cell Institute at the University of Cambridge. "[B]ut we've managed to extract the cells and grow them individually in culture," reported.

The advantage of naive pluripotent stem cells lay in their flexibility as compared to other kinds of stem cells used in scientific pursuits, with theoretically no restrictions on the kinds of adult tissue into which they could develop.

In contrast, unaltered embryonic stems cells (derived from fertilised egg cells) and induced pluripotent stem cells (reprogrammed skin cells) were already primed with instructions to differentiate into particular cell types.

Naive pluripotent stem cells derived from human embryos, on the other hand, did not contain these directions, which allowed a potentially a clean slate for biomedical therapeutic purposes.

"Native stem cells have many potential applications, from regenerative medicine to modelling human disorders," said Guo. The cells held the promise of developing 'healthy' cell treatments for organs and tissues affected by conditions that impede their regular regenerative capacity, including the heart, brain, and pancreas.

When an egg is fertilised, it starts dividing and replicating before the embryo took shape. Around day five, the embryonic cells clustered together and forming a structure called the "blastocyst," made up of three cell types - cells that will develop into the placenta, cells that form the "yolk sac," and the "epiblast" made up of the na´ve cells that will develop into the future body.

The research team removed the stem cells from the blastocyst, on day six, growing them individually in culture.